Lee, Byung-Hwan Choi, Sun-Hye Pyo, Mi Kyung Shin, Tae-Joon Hwang, Sung-Hee Kim, Bo-Ra Lee, Sang-MoK Lee, Jun-Ho Lee, Joon-Hee Lee, Hui Sun Choe, Han Han, Kyou-Hoon Kim, Hyoung-Chun Rhim, Hyewhon Yong, Joon-Hwan Nah, Seung-Yeol 2024-01-20T21:31:55Z 2024-01-20T21:31:55Z 2021-09-03 2009-05 1016-8478 https://pubs.kist.re.kr/handle/201004/132514 Nicotinic acetylcholine receptors (nAChRs) play important roles in nervous system functions and are involved in a variety of diseases. We previously demonstrated that ginsenosides, the active ingredients of Panax ginseng, inhibit subsets of nAChR channel currents, but not alpha 7, expressed in Xenopus laevis oocytes. Mutation of the highly conserved Leu247 to Thr247 in the transmembrane domain 2 (TM2) channel pore region of alpha 7 nAChR induces alterations in channel gating properties and converts alpha 7 nAChR antagonists into agonists. In the present study, we assessed how point mutations in the Leu247 residue leading to various amino acids affect 20(S)-ginsenoside Rg(3) (Rg(3)) activity against the alpha 7 nAChR. Mutation of L247 to L247A, L247D, L247E, L247I, L247S, and L247T, but not L247K, rendered mutant receptors sensitive to Rg(3). We further characterized Rg(3) regulation of L247T receptors. We found that Rg(3) inhibition of mutant alpha 7 nAChR channel currents was reversible and concentration-dependent. Rg(3) inhibition was strongly voltage-dependent and noncompetitive manner. These results indicate that the interaction between Rg(3) and mutant receptors might differ from its interaction with the wild-type receptor. To identify differences in Rg(3) interactions between wild-type and L247T receptors, we utilized docked modeling. This modeling revealed that Rg(3) forms hydrogen bonds with amino acids, such as Ser240 of subunit I and Thr244 of subunit II and V at the channel pore, whereas Rg(3) localizes at the interface of the two wild-type receptor subunits. These results indicate that mutation of Leu247 to Thr247 induces conformational changes in the wild-type receptor and provides a binding pocket for Rg(3) at the channel pore. English KOREAN SOC MOLECULAR & CELLULAR BIOLOGY MOLECULAR-CLONING CHANNEL DOMAIN MUTATION SUBUNIT FAMILY SITES CELLS GENE LOCALIZATION PHARMACOLOGY A role for Leu247 residue within transmembrane domain 2 in ginsenoside-mediated alpha 7 nicotinic acetylcholine receptor regulation Article 10.1007/s10059-009-0073-4 1 MOLECULES AND CELLS, v.27, no.5, pp.591 - 599 MOLECULES AND CELLS 27 5 591 599 scie scopus kci ART001343613 000266349000013 2-s2.0-66649093210 Biochemistry & Molecular Biology Cell Biology Biochemistry & Molecular Biology Cell Biology Article MOLECULAR-CLONING CHANNEL DOMAIN MUTATION SUBUNIT FAMILY SITES CELLS GENE LOCALIZATION PHARMACOLOGY ginsenoside Rg(3) interaction sites mutant alpha 7 nAChR Panax ginseng